How much extra does a copy machine repairman earn per service call in addition to his hourly wage?

The correct answer indicates that the copy machine repairman earns an additional $4 per service call on top of his hourly wage. This means that every time the repairman goes out to service a copy machine, he receives this additional payment, reflecting the extra value of the service provided, which compensates him for his travel and labor beyond his base pay. The additional earnings for each call likely account for factors such as the skill required, the cost of transportation, and the urgency of repairs, which are not included in his hourly wage. Understanding this context helps to clarify how service-based professions often structure their compensation to incentivize performance and ensure that technicians are fairly compensated for their expertise and time.